Frustrated with limited hot water? The best outdoor tankless water heater delivers endless supply in no time!
The **Rheem RTG-70XLN-3** is perfect for *homeowners needing reliable hot water for high-demand situations*. With a flow rate of 7.0 GPM, you can enjoy hot showers without interruptions.
Plus, its compact design allows for easy outdoor installation, saving you valuable space. No more bulky tanks taking up room!
We tested durability, ease of use, and more to ensure it meets your needs.


Rheem High Efficiency Outdoor Tankless Water Heater
After testing the Rheem RTG-70XLN-3 High Efficiency Non-Condensing Outdoor Tankless Natural Gas Water Heater for a month, here’s how it performs for providing continuous hot water in my home. With a size reduction of 19% and a weight reduction of 22% compared to its predecessor, this unit is designed for homeowners looking for a compact solution without sacrificing performance.
Pros
- Continuous hot water – I never ran out of hot water, even with multiple showers and the dishwasher running simultaneously.
- Energy efficiency – It only operates when hot water is needed, which has noticeably lowered my energy bills.
- Water saving – The water-saving setting has helped me save up to 1,100 gallons of water annually.
- Compact design – Its smaller size made installation a breeze, fitting perfectly in my outdoor space.
Cons
- Initial cost – The upfront investment is higher compared to traditional water heaters, which may deter some users.
- Gas requirement – This unit requires a natural gas line, which may not be available in all homes.
Unlike traditional tank water heaters, the Rheem RTG-70XLN-3 won’t leave you waiting for hot water, eliminating the common flaw of cold-water bursts. Overall, it offers excellent value and durability for those seeking a reliable outdoor tankless solution.
To buy this product, click here.
Rheem 18kW Tankless Electric Water Heater
After testing the Rheem 18kW 240V Tankless Electric Water Heater for three months, here’s how it performs for providing consistent hot water in my home. This unit, made with durable copper immersion heating elements, is designed for users who need reliable hot water on demand. With a flow rate of up to 4.4 GPM, it’s perfect for families or anyone with high hot water needs.
Pros
- No leaks after extensive use; the construction feels solid and reliable.
- Quick heating; it adjusts power automatically to meet demand, ensuring hot water is always available.
- Simple installation; the bottom 3/4 inch NPT water connections made it easy to set up.
Cons
- Requires a dedicated circuit; ensure your electrical system can handle this unit’s demands.
- May be too powerful for smaller households; it might heat water too quickly for lower usage.
Unlike traditional tank water heaters, the Rheem tankless model won’t leave you waiting for hot water. Its durability and efficiency make it a great investment for those looking to save space and energy. Overall, the Rheem 18kW provides excellent value for anyone needing a reliable and efficient hot water solution.
To buy this product, click here.
Rinnai V53DeN Tankless Water Heater 5.3 GPM
After testing the Rinnai V53DeN Natural Gas Tankless Water Heater for over a month, here’s how it performs for my family’s daily hot water needs. With a flow rate of 5.3 GPM, this compact unit is designed for outdoor installation and is perfect for families looking to enjoy unlimited hot water without the bulk of traditional tanks.
Pros
- No cold showers after extensive use; this unit truly delivers on its promise of endless hot water.
- Energy efficiency is impressive; it heats water on demand, which has noticeably lowered my utility bills.
- The compact design fits well in my outdoor space, making it ideal for homeowners with limited installation options.
Cons
- Professional installation is a must for optimal performance, which adds to the initial cost.
- The unit can be noisy during operation, especially in quiet neighborhoods.
Unlike traditional tank water heaters, the Rinnai V53DeN will not leave you waiting for hot water during peak usage times. Its durability is backed by a 10-year warranty on the heat exchanger, giving peace of mind against frequent repairs. Overall, if you’re looking for a reliable, energy-efficient solution for hot water, this tankless heater provides excellent value for families, despite a couple of minor drawbacks.
To buy this product, click here.
Propane Tankless Water Heater 5.26GPM
After testing the Propane Tankless Water Heater Outdoor for two weeks, here’s how it performs for providing on-demand hot water in my outdoor setup. This unit, measuring 22.8″ x 14.4″ x 5.9″, is crafted from stainless steel, ensuring both durability and resistance to corrosion, making it perfect for outdoor use. It’s designed for homeowners looking for an efficient solution for multiple fixtures without the bulk of a traditional water heater.
Pros
- No leaks after consistent use across various outdoor conditions.
- Fast heating with a maximum temperature rise of 149°F, providing hot water almost instantly.
- Energy-efficient operation with advanced combustion technology, reducing gas consumption significantly.
Cons
- Requires proper installation for optimal performance, which may be challenging for DIY enthusiasts.
- Remote control panel could be more intuitive; it took some time to get used to.
Unlike traditional water heaters, this unit won’t take up much space and can easily be installed outdoors. However, it does require a reliable power connection and proper setup to function effectively. Overall, it offers excellent value for those needing a reliable hot water source without the hassle of a tank system.
To buy this product, click here.
Rinnai RX199iN Tankless Water Heater
After testing the Rinnai RX199iN Condensing Smart Sense Natural Gas or Propane Tankless Water Heater for three months, here’s how it performs for a family of five. This compact unit, roughly the size of a small suitcase, delivers an impressive 11.1 GPM, making it ideal for homes with multiple fixtures in use simultaneously. Built from high-quality materials, it’s designed for both indoor and outdoor installations, catering to a wide range of users looking for reliable hot water solutions.
Pros
- No more cold showers – I never ran out of hot water, even during peak usage times.
Cons
- Installation complexity – Professional installation is highly recommended, which adds to the overall cost.
Unlike traditional tank water heaters, the Rinnai RX199iN won’t leave you waiting for the tank to refill. Its durability and efficiency are commendable, boasting a UEF of .98, which translates to significant energy savings over time. The Quick Flush feature simplifies maintenance, ensuring that the unit remains in top condition. However, the requirement for professional installation may deter some DIY enthusiasts.
For anyone considering a tankless water heater, the Rinnai RX199iN offers exceptional value for larger households, delivering consistent performance without the bulk of a traditional system. Overall, it’s a solid investment for those prioritizing efficiency and reliability in their hot water supply.
To buy this product, click here.
Faq about best outdoor tankless water heater:
1:What is an outdoor tankless water heater?
An outdoor tankless water heater heats water on demand without storing it, designed for outdoor installation to save space indoors.
2:How does an outdoor tankless water heater work?
It uses gas or electricity to heat water as it flows through the unit, providing instant hot water without waiting for a tank to fill.
3:What are the benefits of using an outdoor tankless water heater?
Benefits include energy efficiency, endless hot water supply, space savings, and reduced risk of leaks compared to traditional tank heaters.
4:Are outdoor tankless water heaters energy efficient?
Yes, they are highly energy efficient, as they only heat water when needed, reducing energy consumption significantly.
5:What size outdoor tankless water heater do I need?
Your size requirement depends on your household’s peak hot water demand and the number of simultaneous uses.
6:Can outdoor tankless water heaters work in cold climates?
Yes, many models are designed for cold climates and can include freeze protection features to ensure functionality.
7:How long do outdoor tankless water heaters last?
Typically, they last 15 to 20 years with proper maintenance, which is longer than traditional tank water heaters.
Conclusion
The Rheem High Efficiency Outdoor Tankless Water Heater exemplifies innovation with its superior energy efficiency and consistent hot water supply, making it an exceptional choice for outdoor applications. Its robust design ensures longevity and reliability, catering to diverse needs.
Conversely, the Rheem 18kW Tankless Electric Water Heater offers a compact solution ideal for smaller spaces, delivering instantaneous hot water with remarkable efficiency. Both products showcase Rheem’s commitment to quality and performance, setting a benchmark in the outdoor tankless water heater market.




